(UNDATED) - Indiana hog farmers are taking precautions against another round of a virus that wiped out five-percent of the nation's pigs last winter.

Cases of porcine epidemic diarrhea virus have declined with warmer weather, but the State Fair still screened all hogs for symptoms last week.

Sarah Ford with the Indiana Pork Producers says more farmers have been inoculating their herds against the virus, and paying extra attention to washing out their trucks. She says the National Pork Board is investing millions in trying to pin down just how the virus spreads and how best to combat it.

Young pigs are susceptible to the virus. Agronomists estimate it killed two-percent of Indiana's piglets over the winter, with many hog-producing states hit even harder.

The virus isn't dangerous to humans, but the reduction in supply has driven pork prices higher.

Ford says farmers should have one advantage this winter: this time, they won't be caught by surprise.